Slip ring



Aug- 13, 1968 I E. MACLIN ETAL. 3,396,586

SLIP RING Filed. Dec. 29, 1965 ,OO 05 lo@ r |22 mu :m ze

94 114 :ff FIG. 4 9@ BYQfmMU//Ml ATTORNEY United States Patent O3,396,586 SLIP RING Ernest Maclin, Paramus, and John L. Bradshaw,Hillsdale, NJ., assignors to General Precision Systems Inc., acorporation of Delaware Filed Dec. 29, 1965, Ser. No. 517,318 1 Claim.(Cl. 74'5) ABSTRACT OF THE DISCLOSURE A slip arrangement for a gyroscopehaving a brush unit and a ring unit, the brush unit being connected tothe outer gimbal having a U-shaped support frame with U-shaped wiresdisposed on opposite sides of rings on a ring unit, the ring unit beingfixed to the inner gimbal disposed coaxially with the brush unit havinga plurality of rings opposite the brush unit wires for contact thereto,the contact surfaces gradually increasing in diameter providing asubstantially frusto-conical profile for ease of assembly with saidwires.

The present invention relates to slip rings, and particularly to a gyrogimbal slip ring.

A conventional gyro gimbal slip ring includes a brush unit having apivot axis and having a plurality of axiallyspaced cantilever-typewires, and includes a ring unit disposed coaxially therein having aplurality of axially-spaced coaxial conductor rings respectivelydisposed oposite to said wires for contact thereto with respectivecontact surfaces of substantially-constant outer diameter arranged toprovide a ring `unit with a substantially-cylindrical outer profile.

One problem with said conventional slip ring is that a special fixtureis used to open up the wire brushes in order to assemble the ring unitcoaxially therein. In certain types of gyroscopes, the slip ring isdisposed in a region within the gyroscope in which it is difficult toapply said special xture for assembly of said slip ring.

In accordance with one embodiment of the present invention, the need fora special xture to open up the wire brushes in order to assemble thering unit coaxially therewith is eliminated, and the assembly of thering unit in the brush `unit is facilitated, by using a ring unit with asubstantially frusto-conical outer profile and with axiallyspacedconductor rings having contact surfaces of step diameters.

Accordingly, it is one object of the invention to provide a slip ringassembly having a ring unit and having a brush unit, which can beassembled without the use of special fixtures.

It is another object of the invention to provide -a slip ring assemblyaccording to the aforementioned object, in which the brush unit has aplurality of wires which apply substantially equal contact forcesagainst said ring unit.

To the fulfillment of these and other objects, the invention provides aslip ring comprising a brush unit having a pivot axis and having aplurality of axially-spaced wires, and a ring unit disposed coaxiallytherewith. Said ring unit has a plurality of axially-spaced coaxialconductor rings respectively disposed opposite said wires for contactthereto with respective contact surfaces of gradually increasingdiameter arranged to provide a substantially frusto-conical profile forease of assembly with said wires.

Other objects of the invention will become apparent upon reading thefollowing description and accompanying drawings, wherein like parts aredesignated by like nummerals throughout the several views, and wherein:

FIG. 1 is a sectional view of a single-axis gyro, embodying features ofthe present invention;

FIG. 2 is an enlarged portion of FIG. 1;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2; and

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 2.

Referring to FIG, l, one embodiment of the present invention is asingle-axis gyro 10. Gyro 10 includes an outer gimbal 12, an innergimbal 14, which is pivotally supported by outer gimbal 12 for pivotalrotation relative thereto, a rotor 16, which is supported by innergimbal 14, and a slip ring means 18, which is pivotally interconnectedto outer gimbal 12 and to inner gimbal 14 for conducting electric powerto rotor 16 from the exterior of outer gimbal 12.

Outer gimbal 12 has a peripheral wall 20 and a longitudinal pivot axis22 and a pair of axially-spaced end walls 24, 26. Wall 24 has an annularbearing portion 28, which projects axially inwardly therefrom and whichsupports an anti-friction ball-bearing means 30. Wall 26 also has ananular bearing portion 32, which projects axially inwardly therefrom andwhich supports an antifriction ball-bearing means 34.

Inner gimbal 14, which is coaxial with outer gimbal 12, has a peripheralwall 36, which is concentric with wall 20 about axis 22, and a pair ofaxially-spaced end walls 39, 40, which are respectively disposedadjacent to walls 24, 26. Wall 38 also has a hollow Ipivot shaft 42,which is journaled in ball-bearing 30; and wall 40 has a pivot shaft 44,which is journalled in ball-bearing 34.

Rotor 16, which is the gyro momentum flywheel, has a drive motor 46 withmotor leads 48, 50, 52 which connect to an exterior power supply (notshown) for supply of electric power to motor 46.

According to the invention, slip ring 18 (FIG. 2), which is coaxial withouter gimbal 12 and inner gimbal 14, includes a ring unit 54, which hasthe shape of a conical frustum and which is fxedly connected to shaft42, and a brush unit 56, which is fixedly connected to wall 24. Brushunit 56 is disposed adjacent to -and radiallyoutwardly of ring unit 54for frictional engagement therewith.

Ring unit 54 includes a plurality of conductor rings 58, 60, 62, whichare axially-spaced along and concentric about axis 22, and which haveradially-outer surfaces or Contact surfaces 64, 66, 68, that graduallyenlarge in outer diameter along said axis 22 and have the shape ofconical frustums. Ring unit 54 also includes a hollow insulation tube 70with a radially-outer surface 72 in the shape of a conical frustum. Tubesurface 72 has a plurality of axialy-spaced annular grooves 74, 76, 78,in which rings 58, 60, 62 are respectively imbedded. Tube 70 has aplurality of leads 80, 82, 84, which connect respectively to rings 58,60, 62 at one end thereof and which connect to motor leads 48, 50, 52 atthe other end thereof. Surfaces 64, 66, 68 are flush with the portionsof surface 72 adjacent thereto.

Brush unit 56 has a U-shaped support frame 92, which is fixedlyconnected to wall 24, and which has a lpair of transversely-spaced walls94, 96 that are disposed on radiallyopposite sides of ring unit 54.Brush unit 56 alsO has a plurality of axially-spaced U-shaped brushes orwires 98, 100, 102, which are preferably pieces of springtempered,round-sectioned wire bent to a U-shape, and has a plurality of leads104, 106, 108, which connect respectively to wires 98, 100, 102.

Wires 98, 100, 102 have respective arm portions 110, 112 and 114, 116and 118, 120, which respectively engage diametrically-opposite portionsof ring surfaces 64, 66, 68, and which are tixedly connected atyopposite ends thereof to walls 94, 96 by cement 122 thereby forming alseries of fixed-ended beams, which are engaged respectively by ringsurfaces 64, 66, 68 substantially at the mid-spans thereof, and whichare equi-distant and symmetrical about axis 22, and which are equallydeflected radially upon assembly thereby applying substantially-equalspring-induced forces on rings 58, 60, 62.

In summary, this invention provides a slip ring assembly having a ringunit and a brush unit which can be assembled without the use of specialxtures, and in which the brush unit has a plurality of wires that applysubstantially-equal contact forces against said ring unit.

While the present invention has been described in a preferredembodiment, it will be obvious to those skilled in the art that variousmodiiications can be made therein within the scope of the invention. Itis intended that the appended claim cover all Such modifications.

What is claimed is:

1. A gyroscope comprising:

an outer gimbal with a pivot axis, said outer gimbal having a peripheralwall and a longitudinal pivot axis and a pair of axially-spaced endwalls respectively having annular bearing portions with ballbearingmeans disposed therein;

an inner gimbal pivotally supported from said outer gimbal coaxiallytherewith, said inner gimbal also having a peripheral wall and a pair ofaxially-spaced end walls respectively having a hollow pivot shaftjournaled in a bearing adjacent thereto and a solid pivot shaftjournaled in a bearing adjacent thereto; a rotor supported by said innergimbal with a drive motor including motor leads connecting to anexterior power supply; and

slip ring means including a brush unit and a ring unit,

said brush unit having a plurality of axially-spaced wires, said brushunit being xedly connected to said outer gimbal coaxially therewith,said brush unit having a Ushaped support frame with a pair oftransversely-spaced walls and further having a plurality ofleadsvrespectively connected to said wires, said wires havingdiametrically-opposite arm portions disposed on either side of rings onsaid ring unit and xedly connecting opposite ends thereof to saidsupport Walls and engaging conductor rings of said ring unit at thecenters thereof, said ring unit being Xedly connected to said innergimbal coaxially therewith and also disposed coaxially with said brushunit and having a plurality of axially-spaced coaxial conductor ringsrespectively disposed opposite said brush unit wires for contact theretowith respective contact surfaces of gradually increasing diametersarranged to provide a substantially frusto-conical profile for ease ofassembly with said wires, said ring unit further having a hollowinsulation tube with a radially-outer surface in the shape of a conicalfrustum and having a plurality of axially-spaced annular grooves inwhich said conductor rings are respectively imbedded and having aplurality of leads connecting to said rings at one end thereof andconnecting to the motor leads of said rotor at the other end thereof,said `rings having respectively radiallyouter surfaces in the shape ofconical frustums and being -ilush with the tube outer surface adjacentthereto.

References Cited UNITED STATES PATENTS 2,942,479 6/ 1960 Hollmann 745.7X 3,005,173 10/1961 Aske S10-232 X 3,074,283 1/ 1963 Quermann 74--5.73,185,951 5/1965 Beau 310-232 X 3,193,636 7/1965 Daniels 339-8 X3,297,973 1/ 1967 Wendell 310-245 X FOREIGN PATENTS 881,299 1l/1961Great Britain.

C. I. HUSAR, Primary Examiner.

FRED C. MATTERN, Examiner.

